I have a 1650x1050 15" panel on this laptop, and web browsing is fine, with the latest browsers and their "zoom" support. Theoretically, you should be able to have a 200DPI display and have everything work.

(I'd swear there's a huge bug in the Firefox image scaling algorithm, but since it's persisted this long it must just be me.... resized images are a bit ugly, but as we move into a world of resolution independence, a period of "ugly" is inevitable, unfortunately.)